a52tofloat32.c

uclinux 下的vlc播放器源代码

/*****************************************************************************
 * a52tofloat32.c: ATSC A/52 aka AC-3 decoder plugin for VLC.
 *   This plugin makes use of liba52 to decode A/52 audio
 *   (http://liba52.sf.net/).
 *****************************************************************************
 * Copyright (C) 2001, 2002 the VideoLAN team
 * $Id: a52tofloat32.c 14954 2006-03-28 21:00:15Z zorglub $
 *
 * Authors: Gildas Bazin <[e-mail]>
 *          Christophe Massiot <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#include <vlc/vlc.h>

#include <stdlib.h>                                      /* malloc(), free() */
#include <string.h>                                              /* strdup() */
#ifdef HAVE_STDINT_H
#   include <stdint.h>                                         /* int16_t .. */
#elif HAVE_INTTYPES_H
#   include <inttypes.h>                                       /* int16_t .. */
#endif

#ifdef HAVE_UNISTD_H
#   include <unistd.h>
#endif

#ifdef USE_A52DEC_TREE                                 /* liba52 header file */
#   include "include/a52.h"
#else
#   include "a52dec/a52.h"
#endif

#include <vlc/decoder.h>
#include "aout_internal.h"
#include "vlc_filter.h"

/*****************************************************************************
 * Local prototypes
 *****************************************************************************/
static int  Create    ( vlc_object_t * );
static void Destroy   ( vlc_object_t * );
static void DoWork    ( aout_instance_t *, aout_filter_t *, aout_buffer_t *,  
                        aout_buffer_t * );
static int  Open      ( vlc_object_t *, filter_sys_t *,
                        audio_format_t, audio_format_t );

static int  OpenFilter ( vlc_object_t * );
static void CloseFilter( vlc_object_t * );
static block_t *Convert( filter_t *, block_t * );

/* liba52 channel order */
static const uint32_t pi_channels_in[] =
{ AOUT_CHAN_LFE, AOUT_CHAN_LEFT, AOUT_CHAN_CENTER, AOUT_CHAN_RIGHT,
  AOUT_CHAN_REARLEFT, AOUT_CHAN_REARRIGHT, 0 };
/* our internal channel order (WG-4 order) */
static const uint32_t pi_channels_out[] =
{ AOUT_CHAN_LEFT, AOUT_CHAN_RIGHT, AOUT_CHAN_REARLEFT, AOUT_CHAN_REARRIGHT,
  AOUT_CHAN_CENTER, AOUT_CHAN_LFE, 0 };

/*****************************************************************************
 * Local structures
 *****************************************************************************/
struct filter_sys_t
{
    a52_state_t * p_liba52; /* liba52 internal structure */
    vlc_bool_t b_dynrng; /* see below */
    int i_flags; /* liba52 flags, see a52dec/doc/liba52.txt */
    vlc_bool_t b_dontwarn;
    int i_nb_channels; /* number of float32 per sample */

    int pi_chan_table[AOUT_CHAN_MAX]; /* channel reordering */
};

/*****************************************************************************
 * Module descriptor
 *****************************************************************************/
#define DYNRNG_TEXT N_("A/52 dynamic range compression")
#define DYNRNG_LONGTEXT N_( \
    "Dynamic range compression makes the loud sounds softer, and the soft " \
    "sounds louder, so you can more easily listen to the stream in a noisy " \
    "environment without disturbing anyone. If you disable the dynamic range "\
    "compression the playback will be more adapted to a movie theater or a " \
    "listening room.")
#define UPMIX_TEXT N_("Enable internal upmixing")
#define UPMIX_LONGTEXT N_( \
    "Enable the internal upmixing algorithm (not recommended).")

vlc_module_begin();
    set_shortname( "A/52" );
    set_description( _("ATSC A/52 (AC-3) audio decoder") );
    set_category( CAT_INPUT );
    set_subcategory( SUBCAT_INPUT_ACODEC );
    add_bool( "a52-dynrng", 1, NULL, DYNRNG_TEXT, DYNRNG_LONGTEXT, VLC_FALSE );
    add_bool( "a52-upmix", 0, NULL, UPMIX_TEXT, UPMIX_LONGTEXT, VLC_TRUE );
    set_capability( "audio filter", 100 );
    set_callbacks( Create, Destroy );

    add_submodule();
    set_description( _("ATSC A/52 (AC-3) audio decoder") );
    set_capability( "audio filter2", 100 );
    set_callbacks( OpenFilter, CloseFilter );
vlc_module_end();

/*****************************************************************************
 * Create:
 *****************************************************************************/
static int Create( vlc_object_t *p_this )
{
    aout_filter_t *p_filter = (aout_filter_t *)p_this;
    filter_sys_t *p_sys = (filter_sys_t *)p_filter->p_sys;
    int i_ret;

    if ( p_filter->input.i_format != VLC_FOURCC('a','5','2',' ')
#ifdef LIBA52_FIXED
          || p_filter->output.i_format != VLC_FOURCC('f','i','3','2') )
#else
          || p_filter->output.i_format != VLC_FOURCC('f','l','3','2') )
#endif
    {
        return -1;
    }

    if ( p_filter->input.i_rate != p_filter->output.i_rate )
    {
        return -1;
    }

    /* Allocate the memory needed to store the module's structure */
    p_sys = malloc( sizeof(filter_sys_t) );
    p_filter->p_sys = (struct aout_filter_sys_t *)p_sys;
    if( p_sys == NULL )
    {
        msg_Err( p_filter, "out of memory" );
        return -1;
    }

    i_ret = Open( VLC_OBJECT(p_filter), p_sys,
                  p_filter->input, p_filter->output );

    p_filter->pf_do_work = DoWork;
    p_filter->b_in_place = 0;

    return i_ret;
}

/*****************************************************************************
 * Open: 
 *****************************************************************************/
static int Open( vlc_object_t *p_this, filter_sys_t *p_sys,
                 audio_format_t input, audio_format_t output )
{
    p_sys->b_dynrng = config_GetInt( p_this, "a52-dynrng" );
    p_sys->b_dontwarn = 0;

    /* No upmixing: it's not necessary and some other filters may want to do
     * it themselves. */
    if ( aout_FormatNbChannels( &output ) > aout_FormatNbChannels( &input ) )
    {
        if ( ! config_GetInt( p_this, "a52-upmix" ) )
        {
            return VLC_EGENERIC;
        }
    }

    /* We'll do our own downmixing, thanks. */
    p_sys->i_nb_channels = aout_FormatNbChannels( &output );
    switch ( (output.i_physical_channels & AOUT_CHAN_PHYSMASK)
              & ~AOUT_CHAN_LFE )
    {
    case AOUT_CHAN_CENTER:
        if ( (output.i_original_channels & AOUT_CHAN_CENTER)
              || (output.i_original_channels
                   & (AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT)) )
        {
            p_sys->i_flags = A52_MONO;
        }
        else if ( output.i_original_channels & AOUT_CHAN_LEFT )
        {
            p_sys->i_flags = A52_CHANNEL1;
        }
        else
        {
            p_sys->i_flags = A52_CHANNEL2;
        }
        break;

    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT:
        if ( output.i_original_channels & AOUT_CHAN_DOLBYSTEREO )
        {
            p_sys->i_flags = A52_DOLBY;
        }
        else if ( input.i_original_channels == AOUT_CHAN_CENTER )
        {
            p_sys->i_flags = A52_MONO;
        }
        else if ( input.i_original_channels & AOUT_CHAN_DUALMONO )
        {
            p_sys->i_flags = A52_CHANNEL;
        }
        else if ( !(output.i_original_channels & AOUT_CHAN_RIGHT) )
        {
            p_sys->i_flags = A52_CHANNEL1;
        }
        else if ( !(output.i_original_channels & AOUT_CHAN_LEFT) )
        {
            p_sys->i_flags = A52_CHANNEL2;
        }
        else
        {
            p_sys->i_flags = A52_STEREO;
        }
        break;

    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER:
        p_sys->i_flags = A52_3F;
        break;

    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARCENTER:
        p_sys->i_flags = A52_2F1R;
        break;

    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
          | AOUT_CHAN_REARCENTER:
        p_sys->i_flags = A52_3F1R;
        break;

    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT
          | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT:
        p_sys->i_flags = A52_2F2R;
        break;

    case AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER
          | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT:
        p_sys->i_flags = A52_3F2R;
        break;

    default:
        msg_Warn( p_this, "unknown sample format!" );
        free( p_sys );
        return VLC_EGENERIC;
    }
    if ( output.i_physical_channels & AOUT_CHAN_LFE )
    {
        p_sys->i_flags |= A52_LFE;
    }
    p_sys->i_flags |= A52_ADJUST_LEVEL;